Liquid cooling system for internal combustion engines



11943. H. N. CHARLES 36,

LIQUID COOLING SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed April 9,1943 my flUbQrTMQ/ Char/e5 Patented Dec. 7, 1943 PATENT OFFICE LIQUIDCOOLING SYSTEM FOR INTERNAL COMBUSTION ENGINES Hubert Noel Charles,Birmingham, England, as-

signor to The Austin Motor Birmingham, England Application April 9,1943, Serial No. 482,456 In Great Britain April 13, 1942 5 Claims.

The invention relates to liquid cooling systems for internal combustionengines.

Experience has shown that, with liquid cooling systems for vehicleengines and the like, substantial advantages accrue by providing twocooling circuits a small or primary circuit and a larger or main coolingcirciut the flow to which is controlled by a thermostatically controlledvalve which does not open until a predetermined temperature of theliquid has been reached.

The main circuit flows from the top of the engine jacket to the top ofthe radiator is usually adequately vented; and, in such passage, isplaced the thermostatically controlled valve, the latter being closedwhen the liquid is below a given temperature. The primary circuitusually comprises a down pipe leading from the engine side of thethermostatic valve to the bottom of the radiator, usually joining intothe usual return pipe from the radiator to the engine.

With the above arrangement a serious diffi culty has been encountered infilling and emptying the cooling system. To overcome this difliculty apermanent vent has been formed through the thermostatic valve which,when the radiator is being filled and the liquid is rising in the enginejacket, allows air to escape from the top of the jacket, through thevent in the valve and so to the top of the radiator.

The provision of a permanent vent in the thermostatic valve has,however, the same efiect as there would be if the valve never closed. Asa consequence, when the liquid commences to circulate, a proportion ofit can flow to the radiator and be cooled thereby instead of flowingsolely by way of the primary circuit constituted by the down pipe. As aresult the heating of the liquid is delayed; and, in very cold weather,the requisite temperature for the proper running of the engine may neverbe attained. The present invention has for its object to provide asystem which is not subject to the above disadvantage, adequate ventingbeing obtained without forming a vent through the thermostatic valve.

According to this invention there is provided a main down pipe whichcommunicates, at its foot, with the bottom of the radiator or with theusual return pipe leading from the bottom or" the radiator to the bottomof the engine jacket or with a chamber communicating with the bottom ofthe radiator and with the said return pipe.

The main down pipe is closed at its upper end Company, Limited,

except for a suitable vent leading to the top of the radiator or to apoint thereabove.

An auxiliary downpipe is taken off from a point on the engine side ofthe thermo-statically controlled valve and is entered, at its highestpoint, into the main down pipe, but not necessarily into the top of themain down pipe. At the point where the auxiliary pipe enters the maindown pipe it is provided with a vent communicating with such down pipe.

As a result of the above, when the radiato is being filled and theliquid rising in the jacket, with the thermostatically controlled valveclosed, the air from the top of the jacket can pass by way of theauxiliary pipe and the vent therein to the top of the main down pipe andfrom thence is vented to the top of the radiator or directly to theatmosphere. Hence the usual vent in the valve is rendered unnecessary.

The auxiliary pipe is preferably led down within the main down pipe tothe bottom thereof, and enters into the said return pipe or the saidchamber. It is open at its lower end and. such end may be presentedtowards the mouth of the return pipe.

When an engine, to which the invention is applied, has been started up,the valve is, of course, shut and the liquid rising in the engine jacketcan flow through the auxiliary pipe to the said return pipe or to thesaid chamber and so back to the bottom of the engine jacket. When agiven temperature is reached the valve opens and the liquid can thenflow by the usual top pipe directly to the top of the radiator andcirculate in the usual way.

Preferably, when the valve has opened to a predetermined degree, theentrance to the auxiliary pipe is closed. This may be effected by theusual sleeve depending from the valve and arranged so that it can coversuch entrance.

The passage between the said chamber (if such is provided) and thebottom of the radiator is preferably partially closed, by a downwardlyextending sill.

As the capacity of the chamber is relatively large the flow of liquid init is relatively slow so that the tendency to cause fall of free surfacelevel in the main down pipe is reduced. Thus the risk of the pump (whichis usually provided) drawing air from the down pipe is avoided.

The pump'is usually provided in the return pipe and the effect of thesill is that it tends to cause liquid (which may have passed the vent inthe auxiliary pipe and passed down the main down pipe) to enter thereturn pipe and not to flow into the bottom of the radiator.

Any liquid which may pass through the vent inthe auxiliary pipe merelyenters the main down pipe and is not lost.

The invention is described with reference to the accompanying drawing,in which:

Figure 1 is a side elevation, in diagrammatic form and partly insection, illustrating a layout of a cooling system according to aconvenient form of the invention, the thermostatic valve being shownopen, the liquid circulating through the radiator in the usual way; and,

Figure 2 is a sectional view of the thermo statically controlled valveand valve chamber to an enlarged scale, the valve in this case beingshown closed.

In the drawing A is the engine jacket, B a valve casing communicatingwith the top of the engine jacket and having a seating b in which isadapted to seat a valve C the stem of which is connected, at its foot,to the top of 'a thermostatic control device D which is anchored at itslower end to a bracket b fixed in, or formed as-part of, the casing, B.Thebracket has apertures, 22 therein to allow of the flow of liquidtherethrough. Secured to the top of the device D is a plate E having adepending flange c (see especially Figure 2) which is a good sliding fitin the casing B. Apertures e in the plate E allow of the flow of liquidtherethrough. The topof the casing 3 above the valve is incommunication, by a pipe F, with the top header 3 of: agradiator F. f isthe bottom header of the radiator. Communicating with this latter is achamber G; but, in the opening between, there is; placed a dependingdeflector or sill g. The otherorouter end of the chamber G is incommunication with a liquid pump'I-I by way of a bottom return pipe handthe delivery side of the pump is in communication, by a short pipe h,with the bottom of the engine jacket.

J is-the main down pipe communicating at its foot, with the top of thechamber G and being closed at its top except for a small vent pipe 7leading to; the top header 7 of the radiator above thefree surface levelwhich is indicated by the chain line at; :13.

From a position inthe wall of the casing D a short distance below thevalve seat I) an auxiliary'pipe K isled off. This latter inclinesupwardlyand at about its highest point enters the main downpipe'J; Itextends downwardly therein and, at its foot, enters the chamber G towhich it is open. The foot of the pipe K is bent somewhat towards themouth of the return pipe h. Where the pipe K enters the pipe J it has avent is: open to the interior of the pipe J.

When the engine is started up under cold conditions, the thermostaticcontrol device D will be holding the valve C on its seat (as shown inFigure 2) and heated' liquid rising in the engine jacket, partly bytherrno-syphon action, but chiefly by the action of the pumpH, will beentirely; prevented from flowing to the top header-fi as there is novent through the valve; but, at such time, thefiange e will be below theentrance to the pipe K so that liquid can flow thereintoand from thenceto thechamber G and to the pump H by which it is returned to the jacket.Any air that may collect in the top of the pipe K can escape bythe-vents 7c and a? to the top: header 1; When the temperature of theliquid reaches a, predetermined degree, thevalve C will open and-causethe flange e to close the entrance to the pipe K. The flow of liquidwill then be wholly through the radiator by way of the pipe F.

The cross-sectional area of the chamber 'G is considerably greater thanthe cross-sectional area below the sill g so that the rate of flow ofliquid in the chamber G will be relatively slow. This ensures that thelevel in the pipe J will not fall appreciably as it otherwise might dounder the action of the pump and allow air to pass into the chamber Gand so to the pump and jacket.

In cold weather the liquid is usually drained ofi if a vehicle is tostand for a relatively long period; and the engine will usually bestarted up before the cooling system is refilled. The liquid is filledinto the radiator in the usual way andwill rise in the engine jacket(and incidentally in the pipes J and K), and, the valve C being closed,the air in the jacket can escape by way of the pipe K and vent k to thepipe J from which it, can pass, by way of the vent pipe 7, to the top ofthe radiator. Any liquid which may pass through the vent is will enterthe pipe J so that it will not be lost to the system.

Having fully described my invention what I claim and desire to secure byLetters Patent is:

1-. A cooling system for an internal combustion engine comprising acooling jacket, a radiator, a top pipe leading from the top of saidjacket to the toprof. said radiator, a bottom return passage leadingfrom the bottom of radiator to the bottom of said jacket, athermostatically controlled-valve adapted to cut on the flow of liquidthrough said top pipe, 2. main down pipe cornmunicating at' its footwith said return passage and being closed at its tep end except tor avent.- passage, an auxiliary pipe ing, from a point between. said jacketand s thermostatically controlled.v valve, to. the said main down pipe,a vent hole in said auxiliary pipe near the top: thereofandcommunicating to the interior oi. the said main down pipe.

2.v A. cooling. system for an internal combusnon engine and comprising acccling jacket, a

radiator, a. top pipe leading from the top of said jacket to. the. top.of said radiator, a bottom return passage leading from the bottom ofsaid radiator to the bottom of said jacket, a thermostaticallycontrolled valve adapted to cut off the flow ofliquid through said toppipe, a main down pipe communicating at its foot with said returnpassage and being closed at its top end except for a vent passage, anauxiliary pipe leading, from a point between said jacket and saidthermostatically controlled valve, to the said mairrdown-pipe andpassing down therein to a point near the foot thereof to which it isopen,

and." a: vent hole in said auxiliary pipe near the top; thereof andcommunicating to the interior of" the said main downpipe.

3. A- cooling system for an internal combustion engine comprisingacooling jacket, 21 radiator, a top pipe leading from the top of saidjacket to the top'of said radiator, a bottom return passage leading fromthe bottom of said radiator to the bottom of said jacket, athermostatically controlled valve adapted to cut ofi the flow of liquidthrough said top pipe, a main down pipe closed at its top end except fora vent passage, an auxiliary pipe leading, from a point between saidjacket and said thermostatically controlled valve, to the saidmain'd'own pipe, a chamber of increased cross section in said returnpassag a. restricted. entrance to. saidmember from the bottom of saidradiator, said main down pipe communicating at its foot with saidchamber and. said auxiliary pipe passing down within said main down pipeto the interior of said chamber to which it is open, and a vent hole insaid auxiliary pipe near the top thereof and communicating with theinterior of said main down pipe.

4. A cooling system for an internal combustion engine comprising acooling jacket, a radiator, a top pipe leading from the top of saidjacket to the top of said radiator, a bottom return passage leading fromthe bottom of said radiator to the bottom of said jacket, athermostatically controlled valve adapted to cut oiT the flow of liquidthrough said top pipe, a main down pipe closed at its top end except fora vent passage, an auxiliary pipe leading, from a point between saidjacket and said thermostatically controlled valve, to the said main downpipe, a chamber of increased cross section in said return passage, adownwardly extending sill at the entrance to said chamber from thebottom of said radiator, said main down pipe communicating at its footwith said chamber and said auxiliary pipe passing down within said maindown pipe to the interior of said chamber to which it is open, and avent hole in said auxiliary pipe near the top thereof and communicatingwith the interior of said main down pipe.

5. A cooling system for an internal combustion engine comprising acooling jacket, a radiator, a top pipe leading from the top of saidjacket to the top of said radiator, a bottom return passage leading fromthe bottom of said radiator to the bottom of said jacket, athermostatically controlled valve adapted to cut off the flow of liquidthrough said top pipe, a main down pipe communicating at its foot withsaid return passage and being closed at its top end except for a Ventpassage, an auxiliary pipe leading, from a point between said jacket andsaid thermostatically controlled valve, to the said main down pipe andpassing down therein to the said return passage to which it is open, anda vent hole in said auxiliary pipe near the top thereof andcommunicating to the interior of the said main down pipe.

HUBERT NOEL CHARLES.

